This invention relates generally to the field of transport refrigeration. More particularly the invention relates to a clamp for mounting a packaged engine-driven electrical generator, or generator set, on a road trailer configured to haul transport containers.
Refrigerated containers are commonly used to transport perishable goods from place to place. Such containers are used in intermodal transportation arrangements, with the containers suitable for loading and transport on ships, trains and truck trailers. The refrigeration systems in such containers require a source of electrical power for operation. When at a freight terminal, a refrigerated container receives electrical power through a connection to a conventional source of electrical power. When in a ship, a refrigerated container receives electrical power from the ship's electrical system. When being transported by road, a refrigerated container must be supplied with electrical power from a portable source. This portable source is commonly a generator set.
One type of generator set is mounted on the trailer by hanging it from the I beams that form part of the chassis of the trailer. It is not economical nor practical to have every container trailer fitted with a generator set nor to have container trailers that are dedicated to hauling only refrigerated containers. Rather, the practice in the industry is to have demountable generator sets that can be installed on a trailer at the same time that it receives a refrigerated container. A generator set is removed from a trailer when the trailer is idle or hauling a nonrefrigerated container.
A generator set is usually mounted by an arrangement of clamps that hold the set to the I beams of the trailer. The clamps must hold the generator set securely to the I beams. Certain important dimensions may vary from trailer to trailer. The widths and thicknesses of the flanges in the I beams that form the main part of the trailer may vary. In addition, the distance between the centerlines of the two I beams used for mounting the generator set may be either 91.4 centimeters (36 inches) or 96.5 centimeters (38 inches). A clamping system must be able to accommodate these dimensional variations.
Prior art clamping systems have as many as 12 vertically oriented bolts that must be tightened to secure a generator set to a trailer. Some prior art clamping systems require that the generator set be placed in position below the trailer with precision before the clamps can be properly made up around the trailer I beams. In the limited clearances and cramped conditions in and around a generator set in place under a trailer chassis, it can be awkward and time consuming to secure a large number of bolts, especially if the bolts are vertically oriented. The limited clearances may make it impossible to use power tools on the vertically oriented clamp bolts. Prior art clamps can make securing a generator set to a trailer a one half man-hour job or more.
What is needed is a clamp for mounting a transport generator set that minimizes the requirement for precision placement of a generator set on a trailer, can accommodate variations in chassis I beam spacing and dimensions, can be quickly made up and secured easily with power tools.